Letter to the editor: 5-year follow-up results of a JCOG1104 (OPAS-1) phase III non-inferiority trial to compare 4 courses and 8 courses of S-1 adjuvant chemotherapy for pathological stage II gastric cancer

Excerpt

Yoshikawa et al. have reported on the long-term follow-up results of the OPAS-1 trial in gastric cancer [1]. The authors compared 4 vs. 8 courses of adjuvant S-1 after radical gastrectomy in patients with pathological stage II gastric cancer. The 5-year overall survival (OS) rates were 89.7% and 88.6% for the 8-course and 4-course arms, respectively, with a hazard ratio (HR) for OS in the 4-course arm of 1.121 (95% confidence interval 0.719–1.749). Based on these results, the authors concluded that an 8-course regimen of adjuvant S-1 should remain the standard adjuvant chemotherapy for pathological stage II gastric cancer. However, there are some issues that need to be considered while interpreting these results. …